By Dave Millhouser

Big Bob was ticked.

The red glow on the dash was irritating and he still had 500 miles to go.

His solution was simple, yet effective. A dab of black tape covered the lens and he cruised back to home base.

Sadly, it was a "hot engine" light, and instead of him replenishing his oil . . . we had to replace his engine. Theres a reason theyre called "idiot lights."

Tire wear (and reliability) has long been one of the coach industrys most significant costs. New technology, in the form of tire monitors with dash displays, has become a major tool in improving tire life and reliability, as well as offering fuel savings.

Some large trucking firms report such systems extend tire life and give a 2 percent improvement in fuel economy, which, over time, pays for the system.

One major coach company thinks they save money, but the big deal for them is that they avoid tire fires and inconveniencing passengers. Good stuff, unless youve got Big Bob at the helm ignoring that nasty warning light.

The systems in large vehicles come in two forms. Some measure air pressure, while others measure pressure and temperature. The problem with sensing only pressure is that your system is only speaking truth before you start rolling.

On the road, when one tire on a dual suffers from low pressure, it runs hotter, and heat expands the air until the pressure in both tires is the same. Sadly, in return for its extra effort, the hot tire wears faster and is more likely to fail catastrophically.

Heat also can be the result of hanging brakes or a failing wheel bearing, each a bad thing. The sooner your driver knows about them the better.

Many coach builders are offering monitoring systems as standard equipment, or installing them on stock buses. This has the effect of putting them in the hands of operators who didnt necessarily choose to have them. Not a bad thing but as one major carriers bus guru says: "These things are only as good as the folks who calibrate, maintain and monitor them."

Therein lies the rub.

A miscreant bus salesman once told of driving a demonstrator coach with the tire monitor signaling distress. His reaction was to rip the unit off the dash.

One manufacturers tech rep had a bus driver beg him to disconnect the gizmo because it had been driving him crazy for days.

The key to using the systems seems to be training. That same tech rep said the systems are reliable, provided the drivers understand them, and technicians install, calibrate and maintain them correctly. Almost all of the problems the rep dealt with were failures of understanding, not of equipment.

The monitors will continue to improve and add features. There currently are systems available for semi trailers that pump air into tires when needed. At some point its likely well see such systems for coaches.

The key to making them work, and taking advantage of all they have to offer, is for operators to "buy in" to the concept. Whether you ordered or inherited a tire monitoring system, it makes sense to teach your drivers and mechanics how it works and how it should be maintained, and take advantage of what it can do for you.

Several modern systems can commune directly with your coachs multiplexed electrical system, opening up a number of intriguing possibilities. The neatest one, so far, literally notifies your facility when tire temperature or pressure reaches pre-set parameters. This way you can call Big Bob and tell him to look at his dash and pull off the road. At this point, the tire billy can become a training aid, fine tuning Bob with a couple of well placed smacks.

A number of carriers have retrofitted systems to existing coaches, after cleverly figuring out that one road call can cost as much as installing the monitor. Whether installed in a new coach, or retrofitted, the key to these jewels helping out is having your staff understand and use them.

Last year, an operator had a new coach burn to the frame in the middle of a charter, 500 miles from home. No one was hurt (unless you count the insurance company).

Several times before the disaster, the driver called dispatch to report the tire monitor was making nasty sounds. He eventually was told the thing had never worked right and to disconnect it.

You guessed it -- a tire fire took out the coach.

(We bus sophisticates refer to such events as thermal incidents.)

Big Bob lives on.

Dave Millhouser is a bus industry marketing consultant and freelance writer. Contact him at: dave_millhouser@hotmail.com.